<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=100%, initial-scale=1.0">
    <title>计算是否闰年</title>
</head>
<body>
    <h1>计算是否闰年</h1>
    <form action="./action.php" method="get">
    输入年份：<input type="number"" name="date"><br>
    <input type="submit" value="提交">
    </form>
</body>
</html>